Alloy.



UNITED sTATEs PATENT oFFio FREDERICK M. BECKET, 0F NIAGARA FALLS,NEW,YORK, ASSIG-NOR TO ELECTED METLIJLURGICAL COMPANY, OF NIAGARA FALLS,NEW YORK, A CORPORATION or WEST vmemra No Drawing.

To all whom it may concern:

Be it known that I, FREDERICK M. BEOKET, a subject of the King ofEngland, residing at Niagara Falls, in the county of Niagara and Stateof New York, have invented certain new and useful Improvements inAlloys, of which the following is a specification. v

This invention is a new alloy containing as essential components iron,chromium, carbon and usually silicon, and distinguished.

Chromium 25 30 Carbon 1.5- 3 Silicon 0.0- 3 Iron 73 63. 5% usuall withtraces of manganese, sulfur,

phosp orus, copper, and perhaps otherelements.

To a lesser, although still marked de ee,

7 this combination of qualities is foun in alloys outside of the rangeabove indicated. For example, alloys containing as low as 20 per cent.and as high as 35 per cent. of chromium, the carbon and silicon beingapproximately as specified above, are serviceable for many of thepurposes mentioned below.

The extreme toughness and hardness of the above-mentioned alloys renderthem highly e1ficient and desirable substitutes for chllled shot andcrushed steelin the cutting and grinding of marble, granite and thelike; and moreover, their freedom from tendency to oxidize or rust inpresence of water presents the advantage that there is no liability tostaining the stone. stance, it is well known that crushed steel cannotbe used for marble-grinding where freedomfrcm staining is of importance;

whereas the present alloys are eminently suited for this use, inaddition tabemg ca- Speciflcation of Letters Patent.

For in Armor.

Patented Nov. 6, 19 17.

Application filed April 10, 1916; Serial No. 90,208.

,pable of much more rapid cutting or grinding. The degree of resistanceto rusting is dependent in a measure upon the silicon-content of thealloy, being more strongly marked as the silicon-content is increasedwithin the limits specified. If however the silicon-content exceedsthese limits a tendency to brittleness is observed.

As an illustration of resistance to oxida-- tion at high temperatures, acast bar of alloy containing chromium 28%, carbon 2.72%, sllicon 0.40%,the balance practically all iron, was exposed continuously at 1100 C; Y

for two weeks to an oxidizing atmosphere in an electrically heated'mufie furnace without undergoing appreciable oxidation, whereas a mildsteel underidentical condi tions was quickly converted into scale oxid.

'Alloys within the limits above specified possess a strongly markedfibrous structure. They can be forged. and machined, although withdifiiculty as compared with ordinaw steel. They can be annea-led'andalso tern pered, and in general are responsive to heat treatment,although to a materially less degree than ordinary high-carbon steels.

Among the uses to which the possession of the above-mentioned propertiesrender the new alloys particularly adapted are mentioned thefollowing 1) As an abrasive. For example the molten alloy may be pouredinto water in order to granulate it, and the resulting granules crushedby stamping or otherwise, and graded, therebv producing irregularlyshaped cutting grains or particles of approximately uniform size. Theabrasive particles may be used as substitutes for chilled shot orcrushed steel in the grinding and cutting of marble and granite asmentioned above, or they may be bonded by a silicate or other bond intoabrasive wheels or other implements, the firing being carried out underordinary conditlons, in case a silicate bond is used. (2) In the form ofcast articles where extreme hardness and toughness are required, as forexam le crusher jaws, stamp shoes, balls and linings for ball-mills, andin general for the wearing parts of milling'and grindin machinery.

(3) a non-slipping surface 1n conjunction with cements, artificial stonecom,-

(4) For the blades of steam turbines, where the highest degree ofresistance to wear and oxidation is required.

(5) For cutting tools.

(6) For high-temperature applications, especially under oxidizingconditions, as for example exposed parts of annealing and peaking ovens,crucibles, furnaces and the The herein-described alloys may be preparedby various methods, as for example by melting commercial grades ofhigh-carbon ferrochromium with the requisite proportion of steel scrapin a crucible furnace, adding if necessary silicon or ferrosilicon. Thecomposition of the component materials being known, the proportions ofsuch ma serials required to produce an alloy of any desired compositionis easily mxnputed arithmetically.

I claim 1. An alloy characterized by a high. de

gree of hardness, toughness and resistance to oxidation, and containing"chromium 20 to 35 per cent, carbon 1.5 to 3 per cent, and

to per cent, carbon 1.5 to 3 per cent., and

silicon 0.0 to 3 pally iron.

3. A tough per cent., the balance princiand substantiallynon-oxidizalole casting composed of an alloy contain ing chromium 20 toper cent, carbon 1.5 to 3 per cent, and silicon 0.0 to 3 per cent, thebalance principally iron.

4. A tough and substantially non-oxidizable casting composed of an alloycontaining chromium 25 to 30 per cent, carbon 1.5

to 3 per cent, and silicon 0.0 to 3 per cent,

the balance principally iron.

lin testimony whereof 1E aifix my signature in presence of twowitnesses.

FREDERIGK M.

Witnesses MARY Scam, SIDNEY Gris.

